A good friend of mine has three teenagers, and they're all fantastic kids, no problems. I asked her a while back what her secret was, and she didn't think she had one! While chatting though, I realised she has a good attitude to their lives, and to her own. She takes an interest, listens to them, leaves them alone if that's what they need. They can talk to her about anything, because she doesn't overreact, and has always answered their probing questions honestly. But the story that summed her up was when her son asked, at 14 or so, to dye his hair green and pierce his ear. She said yes, in the school holidays, he could. Result:- he thought she was cool, she had a tiny bit of control. I thought she'd taken the easy way out, until she said, "Ears can heal up, the dye will grow out. When he asks for a tattoo, I'll say no, and he won't get one, guaranteed." He respects her, and that's where her secret lies!!
It's also well summarised by the saying "Don't sweat the small stuff."
I just hope in ten years' time that will be me with my two..? There's plenty that scares me about the world they will be living in, but I'm already telling my 6 year old that as long as he has a voice in his head telling him what's right and wrong, he will grow into a decent chap! He already understands that.